Chaeto isn’t particularly exacting when it comes to light, which is why you’ll get a wide range of suggestions. I’d personally go with a red spectrum grow light.
Depends what you want. Most lights will grow the stuff. It the fuge is a primary form of nutrient export, BRS has shown that a more powerful light will help. Led grow lights designed for horticulture are a good choice. The Triton Method recommends a T5 fixture.